Regace: a multilateral strategy for integrating solar energy production and crop growth in greenhouse agrivoltaics

The REGACE project (Crop Responsive Greenhouse Agrivoltaics System with CO2 Enrichment for Higher Yields) is a Horizon Europe initiative aiming to develop and validate integrated agrivoltaic solutions tailored for greenhouse environments. The project adopts a multilateral strategy to simultaneously optimize photovoltaic (PV) energy production and crop yield, thereby addressing the dual challenges of sustainable food and energy systems. REGACE spans six pilot sites across Europe and Israel, with the Pontinia greenhouse (FSC) in Italy serving as the focal case study for this abstract. This facility is equipped with 64 custom-designed bifacial photovoltaic (BFPV) modules rated at 75 W each, featuring single-axis tracking and a cell-spacing layout that allows sunlight to reach the crops below. The total peak power of the system is 4.8 kW. One half of the greenhouse is covered with PV modules, while the other half is left uncovered to serve as a reference control for comparative analysis. The project’s innovation lies in the integration of energy and crop production within a controlled greenhouse setting, supported by a robust monitoring framework. Environmental parameters—such as temperature, humidity, CO2, PAR, soil moisture, and illuminance—are tracked at multiple vertical levels. The PV system's performance is continuously assessed inside the greenhouse while a preliminary characterization protocol for Bifacial PV modules has been built and operated on PV modules samples at ESTER lab through MPP tracking, I-V curve analysis, temperature coefficient evaluation, and bifacial gain measurement. The experimental setup within FSC pilot includes custom made automated irrigation managed through MATLAB and a custom made microclimate monitoring system with automatic data management. Crop performance is evaluated via bulk and individual yield measurements. Initial trials with lettuce and zucchini revealed that while crops under the PV-covered section showed slightly reduced yields compared to the open reference area, they still maintained viable productivity, confirming the potential of the agrivoltaic configuration. REGACE thus delivers a pioneering framework for greenhouse agrivoltaics, demonstrating that renewable energy production and high-value agriculture can coexist efficiently. The results provide valuable insights for replicable and scalable agrivoltaic systems that support EU goals for sustainability, food security, and energy transition.